Integrated circuits are used in a wide variety of electronic products. As these products become smaller, lighter and thinner, the need to incorporate high-density integrated circuit (IC) packages increases substantially; however, these high-density IC packages carry with them a penalty of difficulty in interconnecting to a printed circuit board. This problem arises because of the ever-increasing number of terminals or input/output (I/O) pads on an ever decreasing package size. These demands result in the spacings the I/Os decreasing to levels that are difficult if not impossible to routinely solder to the printed circuit board. The net result is that extremely expensive, highly complex placement and soldering equipment is necessary to solder these packages on a circuit board.
Because the tight spacing of the IC package leads requires that the spaces on the printed circuit board be correspondingly small, thereby, increasing the cost of the printed circuit board is increased substantially. The technology used to manufacture printed circuit boards has not kept pace with the technology used to design and manufacture the integrated circuit packages. Therefore, when using the latest state of the art packages, one must pay a penalty in either cost or size of the finished assembly.
It would be highly desirable if a small integrated circuit package could be created that would have a high number of I/Os, yet have a spacing or pitch large enough to accommodate the technology of printed circuit boards.